The subject invention relates to a method and apparatus for forming corrugated board carton blanks in a process wherein corrugated board is formed and die creased and cut into corrugated board carton blanks in a single in-line process.
Cartons for containing bottled products such as but not limited to beer and other beverages and for containing other relatively heavy products are commonly made from corrugated board carton blanks wherein the major surfaces of the corrugated board carton blanks that become the external surfaces of the cartons have printed matter and/or markings thereon such as trademarks, logos, instructions, and other information. Corrugated board beverage cartons and other corrugated board shipping cartons made from such corrugated board carton blanks have the required integrity to contain the weight of such products and cushion such products from external impacts that occur during shipping and handling. Corrugated board shipping cartons are used for packaging product in virtually every industry in the United States and currently account for the largest percentage of shipping containers used in the packaging container business. In addition to being used for shipping cartons, corrugated board is also used for the bracing and blocking of cartons, for partitions within cartons that hold products, e.g. beverage bottles, in place and apart from each other, for cushions between layers of products within cartons and for cushioning heavy products within cartons.
The current practice for making such corrugated board carton blanks, which has been in place for decades, involves a series of separate and individual process steps. In a first in-line process step, an outer liner with printed matter and/or markings thereon, such as trademarks, logos, instructions, and other information, is laminated to a corrugated board having a corrugated medium and an inner liner to form a corrugated board with an outer liner and an inner liner. The corrugated board is then cut into flat rectangular sheets and stacked. In a separate second off-line process step, the flat rectangular sheets of corrugated board are allowed to stand for a predetermined dwell time while the adhesive bonding the outer and inner liners to the corrugated medium sets so that the flat rectangular sheets of corrugated board will have the necessary integrity to undergo the stresses of die-cutting. In a separate third off-line process step, the flat rectangular sheets of corrugated board that are produced in the first and second process steps are individually converted to carton blanks in a die creasing and cutting operation. Where the die-cutter of the die creasing and cutting operation is not provided with full stripping capabilities for automatically removing trim and other pieces of scrap from the blanks being formed, trim and other pieces of scrap are subsequently removed from the corrugated board carton blanks in a separate fourth off-line process step.
As stated above, in the die creasing and cutting process, the corrugated board, made in the first and second separate process steps, is subjected to stresses caused by the creasing and cutting of the corrugated board by the ceasing and cutting die. If the adhesive bonds between the inner and outer liners and the corrugated medium of the corrugated board lack sufficient integrity, one or both of the liners of the corrugated board can be shifted relative to or separated from the corrugated medium during the creasing and cutting process. To be commercially competitive, the corrugated board must be made on the first production line at speeds of hundreds of feet per minute (e.g. 600 feet per minute) and on current production lines, this does not allow the adhesive bonding the inner and outer liners to the corrugated medium of the corrugated board to set up sufficiently to withstand the stresses the corrugated board will undergo during the creasing and cutting operation without a possible displacement of one or both of the liners relative to or separation of one or both of the liners from the corrugated medium. The displacement or separation of one or both of the liners from the corrugated medium of the carton blanks being produced would adversely affect the integrity of the corrugated board carton blanks and the cartons made from the carton blanks. The displacement or separation of the outer liner with the printed matter and/or markings thereon that is to become the exterior surface of the cartons made from the corrugated board blanks can cause the printed matter and/or markings on the corrugated board to be out of register in the creasing and cutting operation so that the creases and cuts formed in the corrugated board and the printed matter and/or markings on the corrugated board are not properly located relative to each other on the corrugated board carton blanks or the cartons formed from the carton blanks. By using the off-line second process step currently employed in the industry to permit the adhesive to set prior to introducing the sheets of corrugated board into the die creasing and cutting operation, the adhesive bonding the liners to the corrugated medium can be allowed to set and form a good bond between the liners and the corrugated medium so that the corrugated board has sufficient integrity to withstand the creasing and cutting operation that forms the corrugated board into carton blanks.
When making carton blanks from a corrugated board, the printed matter and/or markings on the outer liner of the corrugated board that forms the outer surface of the carton erected from the carton blank must be precisely located relative to the creases and cuts made in the corrugated board during the die creasing and cutting operation so that the printed matter and/or markings are properly located on the carton blanks. With the speed that the corrugated board passes through the first process for forming the corrugated board and the need for the precision formation of the creases and cuts in the corrugated board relative to the printed matter and/or markings on the outer liner of the corrugated board, it is again current practice in the industry, which has been in place for decades, to perform the die creasing and cutting operation in the off-line process discussed above.
While the corrugated board carton blanks formed through the use of current industry practices are well made, the need to have a series of separate processes where the corrugated board is first laminated in one process, the adhesive bonding the layers of the corrugated board together is allowed to set in a second off-line process, and then the die creasing and cutting is performed in a third off-line process increases product handling, increases labor costs, requires the storage of the flat rectangular sheets of corrugated board between the first and third process steps, and requires the maintenance of two separate process lines. The method and apparatus of the subject invention solve the problems associated with current industry practices by providing an efficient, cost effective, high output method and apparatus for forming corrugated board carton blanks wherein a corrugated board is formed, adhesive of the corrugated board is set, and the corrugated board is die creased, cut, and stripped of waste to form finished corrugated board carton blanks in a single in-line operation.